During CPR, more chest compressions save more lives

NEW YORK (Reuters Health) - If you're uncomfortable giving mouth-to-mouth resuscitation, you may actually do a better job of cardiopulmonary resuscitation (CPR) if you do less mouth-to-mouth, according to a new study: The odds that someone whose heart has stopped beating goes up markedly when rescuers doing spend more time giving chest compressions, research released this week indicates.

CPR consists of chest compressions and mouth-to-mouth resuscitation, and is performed on people whose hearts have stopped beating. Mouth-to-mouth resuscitation moves oxygen into the lungs of someone who can't breathe on his own, while chest compressions move blood carrying that oxygen to the heart and the brain.

The findings emphasize that "the chest compressions you do on a loved one are one of the most important things that can be done," Dr. Jim Christenson, one of the authors of the study, said in a statement.

"If you feel rusty or are not confident giving mouth-to-mouth ventilation along with chest compressions then just do chest compressions," he continued. "Even by themselves, chest compressions can make a difference."

Christenson, from the University of British Columbia, Vancouver and colleagues examined CPR tracings in 506 patients who suffered "out-of-hospital" cardiac arrest in the US and Canada.

There was roughly a 10 percent increase in the chance of survival for every 10 percent increase in amount of time that rescuers spend giving chest compressions, Christenson and colleagues found.

Specifically, his team found that the heart began pumping blood effectively on its own about 80 percent of the time when rescuers spent most of their time on chest compressions, compared to just shy of 60 percent of time when they spent most of their efforts on mouth-to-mouth resuscitation.

Similarly, about one in eight patients survived long enough to go home from the hospital when rescuers spent most of their time on mouth-to-mouth resuscitation, but that rate of survival doubled when rescuers spent most of their time on chest compressions.

The study appears in the latest issue of the American Heart Association's journal Circulation.

The current study supports another study, which found that cardiac resuscitation designed to maintain nearly uninterrupted chest compressions triples the rate of survival when someone's heart stops beating outside of a hospital. (See Reuters Health report, March 11, 2008).

Collectively, the data from this and other studies suggest that chest compressions should be performed "as much as possible," Christenson said.

SOURCE: Circulation: Journal of the American Heart Association, September 14, 2009.